Improves check for api requests.

Timelines introduces a case where the json format is negotiated
but not represented in the format parameter via routes (i.e., the
extension ".json"). This change adds support for Accept-header content
negotiation, which results in the format field of the request. For
consistency, xml was also added.
[OPF #492] fixes special chars in issue subject
[OPF #487] fixes pagination links

- fixed css for 'prev' and 'next' pagination links
Move ajaxapender.js to separate file.
Move issues.js to separate file and implement client-side quoting for issues.
Add HTML classes to simplify jquery matching.
Implement new route and controller action for issue quotes.
Delete 'journals#new' as journals are not created directly and quoting now uses 'issues#quoted'.
Change link to quoted action to new route.
Use before_filter for new 'quoted' action.
Update 'quote' links and add permission for 'quoted' action.
fixed bad usage of html_safe
[OPF #483] fixes timelog report layout

- added html_safe for timelog report and report_criteria
make code for time entries reports more readable
fixed js error on time report
Introduces strong_parameters whithout making use of it yet

This introduces the strong_parameters gem. It will be default
in rails4 so I consider it a good idea to start using it now.

This commit does not yet make use of the possibilities.
It is intended so we start using it and in order for it to be
available to plugins.
allow travis to run cucumber szenarios
Fix tests.
define the default rake task to run the whole test suite
html mails show a link to an updated attachment instead of just the name (issue #366)